Protective sheath or envelop for liquid-air or liquid-oxygen explosives.



UNITED STATES PATENT OFFICE.

GEoRCi'Es CLAUDE, OF PAR-IS, FRANCE, ASSIGNOR- TO SOCIETE LAIR LIQUL'DE (SO- CIETE ANONYME POUR. LETUDE ET LEXPLOITATION DES PROCEDES GEORGES CLAUDE), or PARIS, FRANCE.

PROTECTIVE SHEATH OR ENVELO]? FOR LIQUID-AIR R LIQUID-OXYGEN EXPLOSIVES.

No Drawing.

tions adapted to be impregnated with liquid air or oxygen and composed of a combustible body such as charcoal, hydrocarbons, or a metallic powder,mixed with some' inert substance,"liieselgulir'for example,to act ,as

a solid diluent. It is necessary in the use of explosive compositions of this kind, which are usually formed into cartridges, to protect them from the: entrance into them of external heat prior to the instant of explosion, since any such entry causes a premature evaporation of the liquid air or oxygen prejudicial to the power of the explosion and to its uniformity. It has been proposed to use protective sheaths or envelops of cardboard or of metal for this purpose, but such materials absorb little or no liquid air or oxygen with the result that they fulfil their function as thermic protectors inefficiently; moreover in the case of cardboard the insufficient quantity of oxygen with which it becomes impregnated by the dipping of the incased cartridges in the liquid before being placed in position causes considerable quan tities of the poisonous gas, carbon monoxid, to be liberated during combustion of the cardboard.

The chief object of the present invention is to provide explosive cartridges of the kind referred to with protective sheaths or envelops capable of absorbing the requisite amount of liquid air or oxygen, and also capable of offering sufficient rigidity to facilitate the transportation of the cartridges and the placing of them in position in mine holes.

According to the present invention the protective sheath or envelop is composed of Specification of Letters Patent.

Application filed February 4, 1913.

Patented Sept. 22, 1914. Serial No. 746,182.

upon the cartridge, thus protected, is received entirely by the sheath or envelop until the liquid air or oxygen with which it has been impregnated is entirely evaporated, whereas in the case of the sheaths hitherto suggested the effect of external heat makes itself felt on the cartridge proper, thus considerably diminishing the explosive power of the cartridge. Moreover the plentiful quantity of liquid air or oxygen contained in the sheath of the present invention tends to burn the carbon monoxidl, if such is formed by the combustion of the cartridge proper.

According to one method of carrying the invention into effect, the inert material employed, kieselguhr for example, is made into an almost fluid paste by mixing it with water or other liquid, and the paste is then spread in a thin layer of uniform thickness over a piece of fabric or very light canvas of appropriate size, the part played by the latter as combustible being negligible. The fabric or canvas, thus uniformly coated with the paste, is then used as a wrapper for the cartridge proper, its size being such as to form a complete envelop. The wrapping may be effected merely by rolling the coated fabric or canvas around the cartridge proper either by hand or mechanically; owing to the plasticity of the paste, it is possible to cause it to extend over slightly more than one complete turn without presenting a visible lapped end or appreciably impairing the cylindrical form of the cartridge as a whole. The ends of the wrapper extending beyond the cartridge ends are turned down upon the latter. The turned-down ends of the wrapper may be tied up, but this precaution is in most cases unnecessary, especially if the enveloped cartridge is treated in the following manner :The enveloped cartridge is dried in a stove or in 'vacuo and is then immersed, until an appropriate degree of absorption has resulted, into a dilute solution of a gummy substance, preferably silicate of potash or of soda. Alternativelythe paste of kieselguhr or other inert material may be formed by using, as the liquid, a dilute solution of a gummy substance as above mentioned, which paste is then applied to the cartridge proper and covered with a piece of fabric or light canvas. A cartridge enveloped as above described possesses a considerable degree of rigidity, and this is accentuated upon immersion in liquid oxygen, thereby affording every facility for its employment.

An alternative method of carrying the invention into effect is to adopt a procedure similar to that resorted to in the manufacture of macaroni. For example the material of the cartridge proper and its enveloping paste may be formed into cylinders simultaneously and concentrically, and the fabric or canvas be applied immediately afterward, the resultant cylinder being cut into convenient lengths to form a series of cartridges.

In the case of cartridges composed of powdered aluminium and kieselguhr cylinders thirty-two millimeters in diameter surrounded by an envelop of kieselguhr three millimeters thick, and immersed in liquid oxygen before being placed in position in a mine hole, the oxygen that has been ab-' sorbed by the envelop takes about four minutes to evaporate. If, instead of taking place in the open air, the evaporation takes place in a cold region, as may be obtained in a very simple manner by drilling the mine hole obliquely or vertically downward, the time occupied in evaporation of the oxygen from the envelop is approximately doubled, and this comparatively long time, in the case of small cartridges, affords the very ample margin of seven minutes in which to do all that is necessary from the time of withdrawing the cartridge from the liquid oxygen. It may be mentioned that in cases where forced filling of the mine holes with cartridges is restored to, the use of enveloped cartridges of the kind above described may necessitate certain precautions for the liberation of the gases evaporated prior to the explosion; a metal or glass tube of small diameter may, for example, be used to serve as a vent.

What I claim and desire to secure by Letters Patent of the United States is 2- 1. A protective sheath or envelop for cartridges adapted for explosion by the aid of liquid air or oxygen, comprising an outside layer of inert porous material capable of absorbing the liquid air or oxygen.

2. A protective sheath or envelop for cartridges adapted for explosion by the aid of liquid air or oxygen, comprising a layer of the same material as that used as diluent in the cartridge proper, said layer enveloping the cartridge proper.

8. A protective sheath or envelop for cartridges adapted for explosion by the aid of liquid air or oxygen, comprising a layer of kies'elguhr enveloping the cartridge proper. 4. A protective sheath or envelop forrartridges adapted for explosion by the aid of liquid air or oxygen, comprising a wrap per composed of inert porous material capable of absorbing the liquid air or oxygen and an outer envelop of fabric.

5.'A protective sheath or envelop for cartridges adapted for explosion by the aid of liquid air or oxygen, comprising a wrapper composed of kieselguhr and an outer envelop of fabric.

6. A protective sheath or envelop for cartridges adapted for explosion by the aid of liquid air or oxygen, comprising an ad: hesively attached outside layer of inert porous material capable of absorbing the liquid air or oxygen.

7. A protective sheath or envelop for cartridges adapted for explosion by the aid of liquid air or oxygen, comprising an adhesively attached layer of kieselguhr enveloping the cartridge proper.

S. A protective sheath or envelo for cartridges adapted for explosion by the aid of liquid air or oxygen, comprising an adhesively attached layer of kieselguhr enveloping the cartridge proper, and an outer envelop of fabric.

9. For producing explosion by the aid of liquid air or oxygen, the combination with a cartridge comprising material combustible by oxidation, and a solid diluent, of a protective sheath or envelop comprising an outside layer of inert porous material capable of absorbing the liquid air or oxygen.

10. For producing explosion by the aid of liquid air or oxygen, the combination with a cartridge comprising material combustible by oxidation, and a solid diluent, of a protective sheath comprising a wrapper composed of inert porous material capable of absorbing the liquid air or oxygen, and anfouter envelop of fabric.

- 1. For producing explosion by the aid of liquid air or oxygen, the combination with a cartridge comprising material combustible by oxidation, and a solid diluent, of a protective sheath or envelop comprising an adhesively attached outside layer of inert porous material capable of absorbing the liquid air or oxygen.

12. For producing explosion by the aid of liquid air or oxygen, the combination with a cartridge comprising material combustible by oxidation, and a solid absorbent diluent, of a protective sheath or envelop EM'LUM V n UM 1mm comprising a layer of the same absorbent a cartridge comprising material combustible material as that used as diluent in the carby oxidation, and a solid diluent, of a protridge proper. tective sheath or envelop comprising a layer 13. For producing explosion by the aid of of kieselguhr and an outer envelop of fabric. 15 5 liquid air or oxygen, the combination with a In testimony whereof I aiiix my signature cartridge comprising material combustible in presence of two witnesses.

by oxidation, and a solid diluent, of a protective sheath or envelop comprising a layer GEORGES CLAUDE 0f kieselguhr. Witnesses: 10 14. For producing explosion by the aid of PIERRE HOU'RLIER, liquid air or oxygen, the combination with I'IANSON C. Coxs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, G. 

